diff --git a/GCC9-buildfix.patch b/GCC9-buildfix.patch
new file mode 100644
index 0000000..03024ad
--- /dev/null
+++ b/GCC9-buildfix.patch
@@ -0,0 +1,46 @@
+commit 37b54179d882fef38ca6735b53e322027414b62e
+Author: Max Kellermann <max@musicpd.org>
+Date:   Wed Apr 3 16:59:53 2019 +0200
+
+    net/IPv[46]Address: add cast to void* to fix GCC9 build failure
+    
+    Fixes:
+    
+     src/net/IPv4Address.hxx: In member function 'constexpr IPv4Address::operator SocketAddress() const':
+     src/net/IPv4Address.hxx:171:24: error: a reinterpret_cast is not a constant expression
+       171 |   return SocketAddress((const struct sockaddr *)&address,
+           |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    
+     src/net/IPv6Address.hxx: In member function 'constexpr IPv6Address::operator SocketAddress() const':
+     src/net/IPv6Address.hxx:138:24: error: a reinterpret_cast is not a constant expression
+       138 |   return SocketAddress((const struct sockaddr *)&address,
+           |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    
+    Closes https://github.com/MusicPlayerDaemon/MPD/issues/522
+
+diff --git a/src/net/IPv4Address.hxx b/src/net/IPv4Address.hxx
+index d8be8e5..c8fead1 100644
+--- a/src/net/IPv4Address.hxx
++++ b/src/net/IPv4Address.hxx
+@@ -163,7 +163,7 @@ public:
+ 	}
+ 
+ 	constexpr operator SocketAddress() const noexcept {
+-		return SocketAddress((const struct sockaddr *)&address,
++		return SocketAddress((const struct sockaddr *)(const void *)&address,
+ 				     sizeof(address));
+ 	}
+ 
+diff --git a/src/net/IPv6Address.hxx b/src/net/IPv6Address.hxx
+index 6f21777..0439c0e 100644
+--- a/src/net/IPv6Address.hxx
++++ b/src/net/IPv6Address.hxx
+@@ -127,7 +127,7 @@ public:
+ 	}
+ 
+ 	constexpr operator SocketAddress() const noexcept {
+-		return SocketAddress((const struct sockaddr *)&address,
++		return SocketAddress((const struct sockaddr *)(const void *)&address,
+ 				     sizeof(address));
+ 	}
+ 
diff --git a/mpd.changes b/mpd.changes
index 77dbd6c..83e1cf7 100644
--- a/mpd.changes
+++ b/mpd.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Tue May 28 12:09:16 UTC 2019 - Christophe Giboudeaux <christophe@krop.fr>
+
+- Add GCC9-buildfix.patch
+
 -------------------------------------------------------------------
 Wed Mar 20 11:10:47 UTC 2019 - Michael Vetter <mvetter@suse.com>
 
diff --git a/mpd.spec b/mpd.spec
index 5028d0e..d161106 100644
--- a/mpd.spec
+++ b/mpd.spec
@@ -40,6 +40,8 @@ Patch0:         %{name}-mpdconf_suse.patch
 Patch3:         mpd-docs.patch
 # PATCH-FIX-OPENSUSE mpd-sndfile.patch
 Patch4:         mpd-sndfile.patch
+# PATCH-FIX-UPSTREAM GCC9-buildfix.patch
+Patch5:         GCC9-buildfix.patch
 %if 0%{?suse_version} >= 1500
 BuildRequires:  libboost_headers-devel >= 1.58
 %else